<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<link rel="stylesheet" href="css/all.css">
	<title>Document</title>
</head>

<body>
	<div class="main">
		<div class="left1"></div>
		<div class="middle">
			<div class="zhongjian1">
				<b class="one"></b>
				<b class="two"></b>
			</div>
			<div class="zhongjian">我是倒三角
				<span></span>
			</div>
		</div>
		<div class="right1"></div>
	</div>
	<!--说明：将带边框的div向左margin负数个单位（margin-left:-1px;），重叠边框，hover时就能显示只有一个边框的效果。同时设置hover的position:relative，使divhover层级高于普通层的层级-->
	<div class="flow">
		<ul>
			<li><a href="#">导航</a><span></span></li>
			<li><a href="#">导航导航导航导航</a><span></span></li>
			<li><a href="#">导航导航导航导航导航导航导航导航导航导航</a><span></span></li>
		</ul>
	</div>
	<script type="text/javascript">
		var str = "acvdfgdhdgdfsfsdfsd";
		console.log(str.substr(3, 3));

	</script>
</body>

</html>